Hook or slider?
Not sure the rigid concept is all that well suited to a rigid hook. Too much torque transmitted to the body.
The RE does need to be pretty darn snug to play to its strength of shape and stationary support. It pretty much needs the slider to negate the torque.
I was using a pivot BRM style set up with my RE for foiling and surfboard use and switched back to a slider. The torque is a lot less and the harness at its best. A rigid hook has way more torque than even the pivot. I have a rigid hook spreader for my RE, but am happy to only use it for under 20% of my riding.
If I were riding a twintip most of the time, I'd use a softer harness.